Improper Fusing: Common Reason for Fires on Boats

Preventing fires in general is very important, but it is even more important while on a boat. The reason for this is that unlike a house, a boat is hard to escape from if it is on fire. And it is important to note that boat fires are commonly caused by electrical issues! For DC systems, an electrical short occurs when positive and negative wires touch without any real resistance between the two. As a result, unlimited current flows through the wires, exceeding the amount that the wire can carry, leading to extremely hot wires. These hot wires could then potentially light something else on fire. To prevent this from happening, our boats have circuit breakers or fuses so that every AC and DC circuit is protected. There are a couple of things to note when it comes to fusing:

  • The placement of each fuse is extremely important because a fuse only protects downstream of where it is located. Therefore, they should always be placed at, or very near to, the source of the power.
  • Every time you change wire size, you have to change the fuse. A big misconception is that any fuse will work, but in reality, you need an appropriately sized fuse.
  • When installing new appliances, there should always be a fuse for the wire and a fuse for the appliance itself.

The ABYC (American Boat and Yacht Council) has specific regulations for the fusing of DC circuits, but when you buy a boat, it is crucial to make sure the wiring is safe. The previous owner or an electrician may have done the wiring but not paid careful attention to some of the points mentioned earlier. As a rule of thumb, if wiring looks messy, it's typically an indication that it should be further examined. It is always best to take the necessary precautions to prevent something like a fire from happening, even if the chances are very small. Something that may seem minor, such as proper fusing, is actually quite important when it comes to safety. If you have any other safety related topics you would like us to write about, please let us know!